As revealed from the documents, the UCLA (University of California and Los Angels) researchers say that the fact that tobacco contains alpha particle emitting substances was known to the cigarette industry as early as 1959.
Polonium-210 can be found in all commercially available domestic and foreign cigarette brands, Polonium is absorbed by tobacco leaves through naturally occurring radon gas in the atmosphere and through high-phosphate chemical fertilizers used by tobacco growers. The substance is eventually inhaled by smokers into the lungs.
The absorbed radiation dose has been estimated to be around 40 to 50 rads by regular smokers over a 20- or 25-year period. These levels of rads, according to the EPA's (US Environmental Protection Agency) estimate of lung cancer risk in residents exposed to radon gas, equal 120 to 138 deaths per 1,000 regular smokers over a 25-year period.
Techniques discovered in 1959 and 1980 to eliminate polonium was not accepted by the industry. The 1980 method, acid-wash technology forms a water insoluble compound when tobacco leaves are treated.
They did not adopt the technique because during the process the nicotine gets ionized and its pass to brain is hampered; depriving the smoker of the good feeling.
The industry also was well aware that the curing of the tobacco leaves for more than a one-year period also would not eliminate the polonium-210, which has a half-life of 135 days, from the tobacco leaves because it was derived from its parent, lead-210, which has a half-life of 22 years.
The insoluble alpha particles form a sticky mass with the resin available in the cigarette smoke and gets deposited at the bifurcation of the main wind pipe, the trachea to bronchus. There, it forms a hot spot for cancer. And it has been seen that the primary lungs cancer most of the time starts from that part. If the person is lucky enough, the alpha particle-irradiated cell may die; if it doesn't, could mutate and become cancerous.
The earliest association of alpha particles to cancer was thought around 1920, when alpha particle-emitting radium paint was used to paint luminescent numbers on watch dials. The painting was being done by hand, and the workers commonly used their lips to produce a point on the tip of the paint brush. Many workers accumulated significant burdens of alpha particles through ingestion and absorption of radium-226 into the bones and subsequently developed jaw and mouth cancers. The practice was eventually discontinued.
Another example is liver cancer in patients exposed to chronic low-dose internal alpha particles emitted from the poorly soluble deposits of thorium dioxide that is present in Thorotrast; a contrast agent used in x-rays imaging. It has been suggested that the liver cancers resulted from point mutations of the tumor suppressor gene p53 by the accumulated alpha particles present in the contrast media. The use of Thorotrast as contrast agent was stopped in the 1950s.
Let us stay safe from First hand, Second hand and Third hand cigarette smoking.